The present invention relates to an adjustable apparatus for retaining a variable number of books on a shelf unit. In particular, the apparatus includes a stationary base which is affixed to an underside of a horizontal shelf and retains books between a vertical support and at least one longitudinally movable vertical bookend through the use of two compressed springs which are located substantially adjacent side edges of the apparatus.
U.S. Pat. No. 2,545,844 to Cougias discloses an adjustable bookrack having book supporting ends slidably interconnected by mating tongue and groove extensions. Two tension springs are located between the supporting ends in tubes which are within central bores. The book-rack serves to maintain books between the supporting ends. The bookrack is in an upright position which rests on top of a shelf.
U.S. Pat. No. 3,389,805 to Yeomans discloses an adjustable telescoping bookend apparatus having upright bookends which are urged together by a centrally located resilient spring. A movable section is supported by wheels which are movable along a stationary section.
French Patent No. 359,275 to Petit discloses an adjustable support which includes two upright fixed supports and a movable support located between the fixed supports. The movable support is resiliently urged toward one of the fixed supports by a centrally located spring. The movable support is guided along tongue and groove elements.
U.S Pat. No. 1,674,582 to Wheeler discloses a bookholder which includes a fixed upright support and a movable support resiliently attached by a centrally located spring. The movable support is guided in a tongue and groove assembly.
U.S. Pat. No. 2,911,103 to Kunkler discloses a device for supporting books which includes two movable upright supports urged together by a centrally located spring.
Although adjustable bookends are known in the art, there are problems with existing structures. It is often desirable to retain a variable number of books on a shelf. While prior bookends may suffice for some applications, there are times when these are not acceptable. Often times in an existing shelf for which books are desired to be retained, there is a need for the overall appearance of the shelf and a bookend to match or blend in with each other. One may be able to locate an adjustable bookend in a color which matches the existing shelving color. However, it would be desirable to have as much of the adjustable bookend out of sight as possible. With existing bookends which are located on top of shelving, a majority of the bookend will always be visible.
Another problem with existing bookends is the size and strength required to support books of sometimes large overall weight on the bookend apparatus. This usually involves a higher cost of production and larger quantities of material for each bookend. Additionally, since the books are placed on a base of the bookend, an adjustable bookend of this type requires a wide flat support surface to support the books.
Yet another problem with adjustable bookend apparatus is a clearance problem associated with some shelving. Often times shelving is sized to accommodate a certain size of book. Although some shelving may allow greater tolerances, others have small tolerances in dimensions such as overall height between shelving. For example, some shelving assemblies include a front face member which extends downward below a shelf a distance to provide the appearance of wide shelving and to improve visual appearance of the shelving. Such an arrangement creates a recessed portion between a lowermost part of the front face member and the bottom of the shelf on which the front face member is attached. This recessed portion defines a space which is not utilized by the shelving since the height of books which can be accommodated is determined by the height between a horizontal support on which the books rest, which may be a lower shelf, and the front face member.
Additionally, in some non-enclosed shelving, there exists a lowermost shelf which is supported a distance above the floor such that books can be placed under the shelf on the floor. In such arrangements, there was either no adjustable support provided or an external bookend apparatus was placed on the floor to retain the books.
There is a need for an adjustable retaining apparatus which can overcome the deficiencies of the prior art and which can utilize existing space for locating an adjustable retaining apparatus without sacrificing height accommodation of books on the shelf.